A discontinuous metal-insulator transition (MIT) from an insulator to a metal occurs without a crystal structure change when an electric field is applied to a VO2 insulator with being changed. The discontinuous MIT phenomenon can be controlled. Details of the discontinuous MIT phenomenon are disclosed in the paper New J. Phys. 6 (2004) 52 (www.njp.org) by the inventors of the present application.
A discontinuous MIT is a first order transition (Mott transition) which causes an abrupt variation of a current with respect to an electric field. Besides the VO2 insulator, several other insulators may show similar characteristics. The abrupt variation of the current with respect to the electric field may be utilized in various electronic devices.
Existing logic circuits generally include silicon semiconductor transistors, which have a complex structure including a semiconductor, an electrode, an insulator, etc. Also, several thin film processes must be performed to form such structure.
In the case of a silicon semiconductor transistor-based logic circuit, thin film processes have been integrated, and manufacturing cost has been increased. Thus, there is great demand for a simple structure which needs fewer process masks and provides a high current gain.